Role of exercise evaluation in restrictive lung disease: new insights between March 2001 and February 2003

Restrictive lung disease is often first detected when patients complain of dyspnea on exertion. Many forms of exercise testing are available, from simple hallway oximetry to the more formal and more complex cardiopulmonary exercise test. Although the use of exercise for diagnosis, treatment, and predicting outcomes is largely understudied in this population, it has recently been shown to be of value in some settings. Exercise testing may be a valuable diagnostic tool in determining the extent of lung disease in sarcoidosis. Medinger et al. reported that the symptom-limited exercise test detected pulmonary dysfunction earlier than history, physical examination, chest radiography, and spirometry alone. Furthermore, Delobbe et al. noted that in patients with biopsy-proved sarcoidosis, cardiopulmonary exercise testing was a more sensitive indicator of early lung disease than pulmonary function tests. The American College of Chest Physicians/American Thoracic Society have published an updated consensus statement for cardiopulmonary exercise testing. Christensen et al. reported that patients with restrictive lung disease may be at risk for hypoxemia with light exercise while on an airplane, and suggest that these patients be considered for in-flight oxygen therapy. Lastly, Herridge and the Canadian Critical Care Trial Group used the 6-minute walk test to prove that survivors of acute respiratory distress syndrome have significant functional limitation 1 year after discharge from the intensive care unit largely secondary to neuromuscular sequelae. Exercise testing appears to be a valuable tool in evaluating, treating, and predicting outcomes in patients with restrictive lung disease. Further study will help to support its use in other restrictive lung diseases.